Appier, 38, was 1-2 with a 4.54 ERA in 10 games, five starts, for Triple-A Tacoma. He started well there after missing the last two weeks of an impressive spring training with a torn calf muscle.
However, the former All-Star and 2002 World Series winner with the Anaheim Angels struggled recently with his control. In 35 2/3 innings for Tacoma, Appier walked 24 and struck out 26.
Appier, who also pitched for the Kansas City Royals, the New York Mets and the Oakland Athletics, last appeared in the majors on April 23, 2004, for Kansas City against Minnesota. He left that game with a strained right
forearm, pain leftover from tendon-replacement surgery in the right elbow in 2003.
He tried a comeback with the Royals in spring training last year but refused a minor league assignment at camp's end and sat out the season.
Appier said Seattle was the only team to call him during the winter.
"I knew I could pitch and wanted another shot," he said in spring training.
Appier was 169-137 in 16 major league seasons. He was an All-Star in 1995 with the Royals, for whom he played from 1989-99 and against in 2003-04.